The gentlemans recreation in two parts : the first being an encyclopedy of the arts and sciences ... the second part treats of horsmanship, hawking, hunting, fowling, fishing, and agriculture : with a short treatise of cock-fighting ... : all which are collected from the most authentick authors, and the many gross errors therein corrected, with great enlargements ... : and for the better explanation thereof, great variety of useful sculptures, as nets, traps, engines, &c. are added for the taking of beasts, fowl and fish : not hitherto published by any : the whole illustrated with about an hundred ornamental and useful sculptures engraven in copper, relating to the several subjects.

CHAP. VIII.

Practical Examples of CHRO∣NOLOGY.

To find the Solar Cycle of any given Year.

TO the Year of our Lord propounded, add 9; then divide the Sum added by 28, and the Remainder is the Solar Circle of the given Year: If nothing remains of the Division, the Number of the Solar Circle is 28.

Note, That the Quotient in this Division shews how many Revolutions of this Circle have been made from our Saviours Nativity to the Year proposed.

'Tis further to be noted, That the Number 9 is therefore added, because that our Saviour being Born in the 10th Year of this Cycle, 9 Years thereof had then past.

To find upon what Day of the Week, the first Day of any assigned Year shall fall.

DIvide the fore-going Year of Christ by 4; then add the Quotient to the Number di∣vided, omitting the remainder of the Division;

from the Sum Total subtract 10, and then divide the residue by 7, and the Remainder from this Division will be the Number sought; or if there be no Remainder, then 7 it self will be the Number. For Example, Let 1654 be the Year proposed, the Year preceding being divided by 4, the Quotient will be 413, which being added to the divided Number, produceth 2066; but 10 being subtracted, 2056 is the remaining Number; which being divided by 7, hath 5 for its Re∣mainder; [ 10] shewing that the first Day of the said Year is the fifth Day of the Week, viz. Thurs∣day.

To find the Dominical Letter of any given Year.

SUbtract the Day of the Week found by the former Rule from 9; for Example, 5 from 9 and there rests 4, which Remainder shews, that the sought Letter is the 4th amongst the Domini∣cals, [ 20] reckoning inclusively from A, whence it fol∣lows that D, is the Dominical Letter of the said Year; for it may be taken for granted from what hath been said before, that A is always affixed to the begining of the Year.

To find out the Bissextile Year.

DIvide the given Year of Christ by 4, if no∣thing remains, then that Year it self is [ 30] it; or if any remain, then the said remainder shews the Number of Years from the Bissextile, both for the time past and that to come; for Example, from the Division of the Year 1654 there rests the Number 2, which shews that 2 Years before, that is 1652 was the last Bissextile, and that 2 Years after, viz. 1656 will be the next.

The Year being given, to find the Number of the Roman Indiction. [ 40]

TO the Year of our Lord proposed add 3, because it is determin'd that our Saviour was born in the 4th Year of this Cycle, so that consequently 3 Years were then past. Now let the Number composed of the said Year and added, be divided by 15, the Number left of the Division will be the Indiction sought; if nothing be left, con∣clude it to be the Year of the Indiction compleat∣ed, [ 50] viz. 15, and the Quotient will shew how many revolutions of this Cycle have past until that given Year. For Example, in the Year 1654, the Year of the Indiction is 7, and there have past to this time 110 Cycles of the Indiction.

To find the Golden Number of the given Year.

TO the given Year of our Lord add 1, which Number divide by 19, the Remain∣der will be the Golden Number of the current [ 60] Year; for Example, The given Year of our Lord being 654, the Golden Number will be 2.

To find the Epact of the given Year.

TO the Golden Number, which is supposed already found, and consists of 3, or a com∣position of several Threes, add 20. The Sum, if it amount not to 30, or the Surplusage if a∣bove, (for then the 30 must be cast away) is the the Epact sought. For Example, The Golden Num∣ber of the Year 1651 is 18, being a multiplicity of Threes, to which 20 added, makes 38; so that after the 30 cast away, the remaining 8 is the Epact of the Year. Otherwise if the Golden Num∣ber should be less by a Unite than 3, or a Com∣position of Threes, then add 10, and the Sum thereof will be the Epact; yet still with a rejecti∣on of 30, when ever there is a Surplusage of that Number. And thus in the Year 1654 the Epact is 12, but if the Golden Number chance to be greater by a Unite than 3, or a Composition of Threes, the Golden Number it self will be the Epact sought.

To find when it will be New-Moon in any given Month.

ADd the Epact of the Current Year to the Number of Months inclusively from March, and Subtract the Product thence arising from 30, or if it exceed that Number, then from 60, and the Remainder will shew the Day of the Month on which the New-Moon happens. For Example, It is inquired on what Day of the Month of August Anno 1651 the New-Moon was, suppose the Epact of that Year was 8, Add there∣unto 6, the Number of Months from March, the Sum of both these Numbers will be 14; then Subtract from 30, and there remains 16; whence it is apparent, that the New-Moon of that Month was about the 16th Day.

To find the Age of the Moon on any Day given.

HAving from the foregoing Problem gained the New-Moon, if the given Day of the Month be after the New-Moon, reckon how many Days inclusively have past from thence; but if before, it will belong to the last part of the pre∣ceding Moon. For Example, If the Age of the Moon be sought on the 24th of August in the Year 1651, in which the New-Moon is found to fall on the 16th Day, by consequence it may be concluded, that she was 9 Days Old; but if it be sought on the 8th of August, it was on the 22 of the Moon preceding; upon this Hypothesis, that 30 Days are attributed to the Moon; for if from 30 you Subtract the Days numbred from the New-Moon found, and consequently from the end of that preceding Moon which is found to be 8, there remains 22.

There is another Vulgar way of finding the Age of the Moon. Add together these 3 Numbers, the proper Epact of the Year, the Number of Months inclusively from March to the given Month; and lastly the given Day of that Month. If the Sum of these Numbers added be under 30, it shews the Age of the Moon; if above 30,

then Subtract 30 from it, and the Remainder will be the Age of the Moon sought.

Note, That when the Age of the Moon is sought in the Month of January, or March, nothing is to be added to the Epact, but the Day of the Month, and that only 1 is to be added for the Month of March, and April. But remember, that that Epact begins from January.

The Age of the Moon being known, to assign its [ 10] place in the Zodiack.

SUppose that on the 31th of October the Sun be in the 8th Deg. of Scorpion, and that the Moon be at that time 16 Days Old, conse∣quently that 16 Days before she was in Con∣junction with the Sun in the 23th Degree of Libra; and lastly that the Moon in one diurnal Circuit passeth through very near 16 Degrees of the Zodiack: Hereupon multiply those 16 Days [ 20] by the 13 Degrees, and the Product will shew how many Degrees she is distant from the Sun; then by reckoning the Degrees which the Sun hath finish'd at that time, and knowing how many Degrees the Moon hath departed from the Sun, it may consequently be collected in what Sign the Moon is, and in what Degree of the Sign, since every Sign contains 30 Degrees. Or thus, multiply the Age of the Moon by 4, and again the Product of this Multiplication by 3, [ 30] and you will have the Number of Degrees of the Moons distance from the Sun.

Note, That the Moon departs every Day far∣ther and farther from the Sun about ¼ of an Hour; so that if she riseth to Day with the Sun, to Morrow she riseth not till ¼ of an Hour after.

To find the Paschal Moon of any given Year.

SEek in the Gregorian Calender, from the 8th [ 40] of March to the 5th of April, for the Epact of the Year current, and that will shew that the New-Noon is on such or such a Day; then reckon 14 Days from thence, which done, seek the Dominical Letter, which follows next after the said 14th Day; and hereby the true Time of the Feast of Easter is known.

Note, That these Moons only which begin at the 8th of March, and end at the 5th of April, [ 50] can become Paschal, and consequently that Easter can't fall sooner than the 22th of March, since the 14th Day of the Moon falls upon the 21th of March, and the Day following is the Domi∣nical, or Lords Day, which is Sunday. But neither on the other side can Easter fall later than the 25th of April; and consequently, it is also to be observed, that a March Moon, that is, whol∣ly within the Month, can never become Paschal, since (as it hath been already observed,) the [ 60] Moon is only attributed to that Month in which it ends; but the Paschal Moon always ends out of the Month of March; whence it follows, that a March-Moon can never be Paschal; or a Moon of the first Month, according to the Jews, and the Decree of the Nicene Council.

The time of the Day, or Night being given, to find what a Clock it is.

FIrst, Let the Suns Elevation above the Ho∣rizon be known, and the Degrees of the Zodiack, which the Sun or Moon possesseth, be rightly disposed in the Circle of the Elevation; then apply the Ostensor to that Deg. or part of the Zodiack, according to the Line of Direction, which upon the Limbo will point to the Hour sought; that is, if in the East-part, the Anti∣meridian, or Forenoon-Hours; if in the Western∣part, the Pomeridian, or Afternoon-Hour.

Where Note, That Equal, or Equinoctial Hours are here treated of; for if an Vnequal, or Temporary-Hour be sought, the Ostensor is ap∣plied to the part opposite to the Sun, or to the opposite Sign and Degree in the Zodiack; the lower part of the Ostensor will denote the Vn∣equal.

To find the Rising, and Setting of the Sun; and consequently the quantity of the Artificial Day, at any time of the Year.

PLace the Part, or Degree of the Sun, found by the Astrolabe, on the Eastern part of the Horizon; then set the Ostensor to that part of the Sun, and it shews the sought Hour of the Suns-Rising. In like manner the Hour of the Suns-Setting, is to be found by transferring that of the Zodiack where the Sun is to the Western Horizon.

The same is also done by the Globe, or Ar∣millary Sphaere, by applying that part of the E∣cliptick where the Sun is, to the Meridian-Circle, and at the same time putting the Horary Index upon the Meridian-Hour; and lastly, turning that part of the Zodiack Eastward, till it exactly answer the Horizon and then the Horary-Index will shew at what Hour the Sun Riseth: In like man∣ner answerably for finding the Hour of the Suns-setting.

Of the Morning and Evening Crepuscle, or Twi∣light.

THe Morning Crepuscle begins when the Sun comes within 18 Degrees of the Horizon, towards his Rising in the Morning; the Evening Crepuscle ends when the Sun Setting is gone 18 Degrees beneath the Horizon. To find the Hour of this Crepuscle, turn the Globe so about, that that part of the Ecliptick where the Sun is, may fall 18 Degrees beneath the Horizon, and then the Horary-Circle will declare the sought Hour; and so the opposite part being Elevated 18 De∣grees above the Horizon, proves that the Sun at the same time is descended 18 Degrees beneath, as will appear by numbring those Degrees upon the Aequator.

To know what A-Clock it is in any part of the World.

THis will easily be found by the help of the Terrestrial Globe; the Hour being first known of those Regions which lye under your Meridian, by moving that Meridian, and di∣rectly applying it to the immoveable Meridian of your Instrument, and placing the Horary-Index [ 10] at such or such an Hour; then upon turning about the Globe, the Immoveable Meri∣dian will point out those Regions, whose Hour de∣sired is shewn in the Horary-Index.

First, It is to be noted, for the unfolding of several Problems of this nature, That the Earth is daily surrounded by the Sun, who in that Quotidian Course passeth through a multitude of Meridians, successively one after another; so that he must visit every Hour, 15 Meridian, accord∣ing [ 20] to the Account of 365, being divided by 24. Moreover, It must be allowed, that in every Country there is a Mid-day, or Noon, when the Sun makes its Circle, which is thence called the Meridian-Hour, the very midst of the said place, and consequently, that every 15 Meridians he passeth through, so many Hours he makes; and that the Sun makes at the same time both the same Hours, and also both new Hours and Sea∣sons respectively, according to the several Coun∣tries [ 30] and Regions he passeth through; whence it may well enough be affirmed, That that very mo∣ment there is at one and the same time every Hour and every Season of the Year throughout the several Countries of the World, in so much that every Hour of the day perpetually circuits round about the Earth, &c. Suppose therefore, that to a man resting under the same Meridian there is alwaies a natural Day of 24 Hours, be∣cause there must needs be such a space of Time before the Sun can return again to the same Me∣ridian.

Note also, That to a Man journying Eastwards, the Day is less than 24 Hours: for the Sun will be sooner in that Meridian in which he is to meet him, than in that from whence he departed. On the contrary▪ to one that makes a Journey West∣wards, the Day becomes more than 24 Hours, because the Sun will sooner reach the Meridian from whence the Person departed, than to over∣take the Person departing: Wherefore, Note in the last place, That it may so happen that two Ships setting forth from the same Port, the one Eastwards, and the other Westwards, yet at length may meet in some part of the World. In like manner, Admit Peter go hence Eastward, and Paul at the same time Westward, and both of them having surrounded in their Travels the World, after some Years, return on the same Week to John, who remains all this while at Home; it may happen that although every one of them observe the same way of counting the Time, yet John may reckon Tuesday; Peter, Wednesday; and Paul, Munday; then the next day after Peter may have Thursday, John Wednesday, and Paul, Tuesday; lastly on the day following, Peter may reckon Fryday, John Thursday, and Paul Wednes∣day, and so of the rest; so that in one and the same Week in reference to 3 Men, Thursday will be thrice reckoned.

Hence comes the Solution of a common Para∣dox, maintaining, That it may so happen that two Brothers born at the same time, shall also dye to∣gether, and yet one live longer than the other, because he hath numbred more Days.